Trait mariadb::storage::Handler

pub trait Handler: 'static {
    type Handlerton: Handlerton;

    const SUPPORTS_INDEX: bool = false;
    const MAX_SUPPORTED_RECORD_LENGTH: usize = 65_535usize;

    // Required methods
    fn new(table: &TableShare<'_>, mem_root: MemRoot<'_>) -> Self;
    fn open(name: &Path, mode: Mode, open_options: OpenOp) -> StorageResult;

    // Provided methods
    fn create(
        &self,
        name: &CStr,
        form: TableShare<'_>,
        create_info: &CreateInfo<'_>
    ) { ... }
    fn table_flags(&self) -> TableFlags { ... }
    fn write_row(buf: &CStr) { ... }
    fn update_row() { ... }
    fn delete_row() { ... }
    fn delete_all_rows() { ... }
    fn store_lock(&self) { ... }
    fn scan_time(&self, ctx: HandlerCtx<'_>) -> IoAndCpuCost { ... }
    fn rnd_pos_time(&self, ctx: HandlerCtx<'_>, rows: usize) -> IoAndCpuCost { ... }
}

Required Associated Types

type Handlerton: Handlerton

Provided Associated Constants

const SUPPORTS_INDEX: bool = false

Set this to true if index support is available. If so, this type must also implement IndexHandler.

const MAX_SUPPORTED_RECORD_LENGTH: usize = 65_535usize

Required Methods

fn new(table: &TableShare<'_>, mem_root: MemRoot<'_>) -> Self

Create a new handler

When is this called?

• Every time there is a new connection

fn open(name: &Path, mode: Mode, open_options: OpenOp) -> StorageResult

Open a table, the name will be the name of the file.

Closing happens by dropping this item.

When is this called?

Not for every request, more to come…

Provided Methods

fn create( &self, name: &CStr, form: TableShare<'_>, create_info: &CreateInfo<'_> )

Create a new table and exit

This should

When is this called?

• SQL CREATE TABLE statements

fn table_flags(&self) -> TableFlags

fn write_row(buf: &CStr)

This is an INSERT statement

fn update_row()

fn delete_row()

fn delete_all_rows()

Delete all rows

When is this called?

• SQL DELETE with no WHERE clause

fn store_lock(&self)

fn scan_time(&self, ctx: HandlerCtx<'_>) -> IoAndCpuCost

Time for a full table data scan

fn rnd_pos_time(&self, ctx: HandlerCtx<'_>, rows: usize) -> IoAndCpuCost

Cost of fetching rows records through rnd_pos.

Object Safety

This trait is not object safe.

Implementors